Change of surface property of dental impression materials according to time and disinfection

The purpose of this study was to investigate the hydrophilicity of dental impression materials. Two ultrahydrophilic (Fusion, Genie) and four hydrophilic (Imprint II, Aquasilultra, Twinz, Perfect‐F) impression materials were used. Initially, 0.5% NaOCl and 1% povidone were used as disinfectants. In order to investigate the change of the surface wettability of impression materials according to the elapsed time after mixing, the contact angles were measured at 30 s and 2 min after mixing, respectively. Contact angles were also measured before and after disinfection. The contact angles of the ultrahydrophilic impression materials were lower at 2 min than at 30 s, whereas those of the hydrophilic impression materials showed the opposite result (p < 0.05). Fusion and Perfect‐F had higher contact angles in the NaOCl‐group and lower contact angles in the povidone‐group than those of nondisinfection group (p < 0.05). The contact angles of Aquasilultra and Twinz in the povidone‐group were higher than those in the nondisinfection group (p < 0.05). The elapsed time after mixing and disinfection of impression materials affected the contact angle of water on the surface of the impression materials. These results suggested that impression materials should only be used within the scope that their wettability is not degraded. Copyright © 2008 John Wiley & Sons, Ltd.